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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . P O W T E N _ F L T --
-- --
-- S p e c --
-- --
-- Copyright (C) 2020-2024, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package provides tables of powers used for real conversions
package System.Powten_Flt is
pragma Pure;
Maxpow_Exact : constant := 10;
-- Largest power of five exactly representable with Float. It is equal to
-- floor (M * log 2 / log 5), when M is the size of the mantissa (24).
-- It also works for any number of the form 5*(2**N) and in particular 10.
Maxpow : constant := Maxpow_Exact * 2;
-- Largest power of five exactly representable with double Float
Powfive : constant array (0 .. Maxpow, 1 .. 2) of Float :=
[00 => [5.0**00, 0.0],
01 => [5.0**01, 0.0],
02 => [5.0**02, 0.0],
03 => [5.0**03, 0.0],
04 => [5.0**04, 0.0],
05 => [5.0**05, 0.0],
06 => [5.0**06, 0.0],
07 => [5.0**07, 0.0],
08 => [5.0**08, 0.0],
09 => [5.0**09, 0.0],
10 => [5.0**10, 0.0],
11 => [5.0**11, 5.0**11 - Float'Machine (5.0**11)],
12 => [5.0**12, 5.0**12 - Float'Machine (5.0**12)],
13 => [5.0**13, 5.0**13 - Float'Machine (5.0**13)],
14 => [5.0**14, 5.0**14 - Float'Machine (5.0**14)],
15 => [5.0**15, 5.0**15 - Float'Machine (5.0**15)],
16 => [5.0**16, 5.0**16 - Float'Machine (5.0**16)],
17 => [5.0**17, 5.0**17 - Float'Machine (5.0**17)],
18 => [5.0**18, 5.0**18 - Float'Machine (5.0**18)],
19 => [5.0**19, 5.0**19 - Float'Machine (5.0**19)],
20 => [5.0**20, 5.0**20 - Float'Machine (5.0**20)]];
Powten : constant array (0 .. Maxpow, 1 .. 2) of Float :=
[00 => [1.0E+00, 0.0],
01 => [1.0E+01, 0.0],
02 => [1.0E+02, 0.0],
03 => [1.0E+03, 0.0],
04 => [1.0E+04, 0.0],
05 => [1.0E+05, 0.0],
06 => [1.0E+06, 0.0],
07 => [1.0E+07, 0.0],
08 => [1.0E+08, 0.0],
09 => [1.0E+09, 0.0],
10 => [1.0E+10, 0.0],
11 => [1.0E+11, 1.0E+11 - Float'Machine (1.0E+11)],
12 => [1.0E+12, 1.0E+12 - Float'Machine (1.0E+12)],
13 => [1.0E+13, 1.0E+13 - Float'Machine (1.0E+13)],
14 => [1.0E+14, 1.0E+14 - Float'Machine (1.0E+14)],
15 => [1.0E+15, 1.0E+15 - Float'Machine (1.0E+15)],
16 => [1.0E+16, 1.0E+16 - Float'Machine (1.0E+16)],
17 => [1.0E+17, 1.0E+17 - Float'Machine (1.0E+17)],
18 => [1.0E+18, 1.0E+18 - Float'Machine (1.0E+18)],
19 => [1.0E+19, 1.0E+19 - Float'Machine (1.0E+19)],
20 => [1.0E+20, 1.0E+20 - Float'Machine (1.0E+20)]];
end System.Powten_Flt;
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